Valve-operating mechanism



C. B. KIRKHAM. VALVE OPERATING MECHANISM. APPLICATION HLED AUG. 10, I917.

1,373,432. Patented Apr. 5, 1921.

gvwemtoz CHAELEQB. KHQKHAM.

EsD S AYES N ll PATENT QFFECE.

CHARLES B. KIRKHAM, OF BUFFALO, NEW YORK, ASSIGNOR TO GURTISS AEROPLANE AND MOTOER. CORPORATION, A. CORPORATION OF NEW YORK.

VALVE-OPERATING- MECHANISM.

Specification of Letters Patent.

Patented Apr. 5, rear.

Application filed August 10, 1917. Serial No. 185,518.

To all whom it may concern:

Be it known that I, CHARLES B. KIRKHAM,

a citizen of the United States, residing at Buflfalo, in the county of Erie and State of New York, have invented certain new and useful Improvements in Valve-Operating Mechanism, of which the following is a specification.

My invention relates to internal combustion engines of the multicylinder type and more particularly to the valve operating mechanism therefor. p

In order to meet the requirements of the present day for high speed operation as well as maximum power per unit of weight, it is almost imperative that multiple valves be used. It is also a well known fact that the valve which gives the best service is the type which is located directly in the head of the cylinder. In the event, however that two or more intake and exhaust valves are used for each cylinder, the problem of op another, all of which adds unnecessarily to the number of parts and consequently to the weight of the motor as well. that the motor is designed for excessively high speed the wear and tear on this large number of parts also becomes a highly important factor in determining its practica bility. 1

The valve mechanism of my invention is not subject to the above mentioned objections. by reason of the fact that the use of long tappet rods and rocker arms is entirely eliminated. Moreover, the arrangement of the valves, for instance two intake and two exhaust valves per cylinder, is such that all four valves may be simply and effectively operated b means of a single overhead cam shaft which engages the valves of each pair 'by means of a simple intermediary cam follower.

As will appear later,.this arrangement is made possible because of the fact that the valve cage structure per se'is so arranged that adequate support and accommodation IS 1provided for receiving and retaining the va ves and valve stems and the cam follower together with the bushings within which they operate. The bearings for the overhead cam shaftalso are carried directly upon this unitary valve cage structure.

In the event In describing my invention in detail, reference is made to the drawings, in which:

Figure 1 is a sectional view through a cylinder showing the arrangement of parts; lfig. 21s a partial view of a steel cylinder llning used in connection with the motor, and

Fig. 3 1s a fragmentary detail view of the camfollower.

In the motor in which my invention is embodied at this time, the main cylinder jackets 5 are cast integrally with the upper half of the crank case 6 of the motor (not shown) and are provided at their upper extremitles with suitable flanges 7 adapted to receive bolts or studs for retaining a valve cage structure 8. The valve cage structure 8 is arranged so that it is common to a mul tiple number of cylinders and is provided on its lower side with a threaded retaining wall 9 into which the enlarged and thickened explosion chamber 10 of the steel cylinder '11 is screwed. This cylinder 11 as will be seen by reference to Fig. 2 is formed in one solid piece and carries adjacent its lower extremity a flange 12 which is adapted to bear upon suitable packing material13 carried within an annular packing recess 14 formed within the lower portion of the main cylinder casting as shown in Fig. 1.

The usual typeof puppet valves 15 are used, their stems operatlng within steel sleeves or bushings 16 which are pressed within the web structure 8. These bushings 16 -are exteriorly flanged at a medial point and are pressed securely into the web portion 17 formed within the main valve cage casting with their flanges 18 seated at the bottoms 19 of recesses formed at the mouths of the bushing openings. These flanges 18 also serve as seats for the lower extremities of, the valve operating springs 20. The upper extremity of the valve springs 20 bears upon a pressed metal cap 21 which is attached to. the upper extremity of the valve stems 22 by means of split tapered washers 23 which engage downwardly tapered portions 24 provided on the valve stems.

Both valves of a pair are simultaneously operated fromoan overhead *cam shaft 25 which is supported in suitable bearings 26' carried upon the upper portion of the main valve cage structure 8. The cam shaft 25 carries a number of cams 27 i which bear di-' rectly upon T-headed cam followers 28. The

shank 29 of the cam follower operates within a steel bushing 30 which is pressed into the main valve cage structure. The branches of the cam follower adjacent their extremi ties bear upon the valve stems. The cam follower is engaged directly by the cam at a point intermediate its ends and substant-ially just over its shank. More specifically it may be said that the follower yokes the valves together and is itself directly engaged by the cam in the medial plane of its support.

In order that the valves 15 may be prop: erly adjusted, the cam follower 28 is provided with adjusting plugs 31 which are" threaded into it. These plugs 31 are socketed on their underneath side to receive the extremities of the valve stems. Referring to Fig. 3 it may be seen that the head of the cam follower which retains the adjusting plugs 31 is kerfed as at 32 and pro vided with a transversely extending screw 33. It may be seen, therefore, that when the plugs 31 have been properly adjusted, they may be clamped securely in place by means of the screws 33.

In addition to retaining the cylinders within its lower side the valve cage structure 8 contains the inlets and outlets which lead to the intake and exhaust manifolds. It is provided with a web structure of such form that the valve stems and their operating mechanism are suitably supported. By thus constructing the valve cages, there is provided ample'space for cooling water to circulate around the valves. In order to inclose the cam shaft and valve mechanism the housing cover 34 which is adapted to be bolted to the upper portion of the valve cage casting is provided.

Although I have described more or less detailed forms of my invention, it is to be understood that interpretationthereof should be made only in view of its generic spirit.

lVhat is claimed is:

1. A valve mechanism for internal combustion engines comprising a valve cage structure having valve stem openings formed therein with recessed mouths,

flanged valve stem bushings in said openingswith their flanges seated in said recesses, a pair of similarly cluiract'erized valves having their stems projecting through said bushings, a recess in said cage structure intermediate said valves having a flanged mouth, a flanged follower bushing seated in said recess with its flange hearing on the head of the recess flange, a T- headed follower having its shank guided by said follower bushing and bearing by its head on said valve stem, and a cam engaging the head of said T-follower at an intermediate point together with yielding means engaging the valve stem bushings to retain the valves upon their seats. I

2. In a multicylinder internal combustion engine in combination, a unit valve cage mounted upon the cylinder heads, a pair of similarly characterized valves for each cylinder, said'valve cage having recessed openings in alinement with said valves and said valves having stems extending upwardly through said openings, retaining springs surrounding and engaging said stems and disposed in the recesses, a transverse cam shaft journaled upon said cage, and a T-shaped follower for each of said pairs of valves, the head of which follower is disposed between said cam shaft and the valve stems and is engaged thereby, the shank of said follower being disposed in a guide opening formed in the cage and between the valves of each pair.

3. In a multi-cylinder internal combus tion engine, in combination, a unit valve cage mounted upon the cylinder head, said valve cage having valve stem openings formed therein with recessed mouths, flanged valve stem bushings in said openings with their flanges seated in said recesses a pair of similarly characterized valves having their stem projecting through said bushings, a recess in said cage structure intermediate said valves, a T headed follower having its shank guided in said recess and bearing by its head on said valve stems, and a cam engaging the head of said T follower at an intermediate point, together with yielding means disposed in the recessed mouth and engaging the valve stems to retain the valves upon their seats.

4. A valve mechanism for internal com bastion engines comprising a unit valve cage structure having valve stem openings formed therein with recessed months, a pair of similarly cluiracterized valves having their stems projecting through said recessed months. a recess in said cage structure intermediate said valves. a T headed follower having its shank guided within said intermediate recess and hearing by its head on said valve stems, springs surrounding and engaging said valve stems and disposed within said recessed months for retaining the valves in a closed position, and a cam engaging the said T follower at an intermediate point.

In testimony whereof I hereunto aflix my signature.

CHARLES B. K IRKHAM. 

